The colony of monkeys is well established and after some initial problems associated with diet is thriving. Blood samples are reqularly collected and comprehensive analyses performed to monitor the health of the animals. It has now been clearly established that monkeys can be maintained on a diet all the components of which are are normally purchased for human consumption. The levels of serum and salivary immunoglobulin are monitored on a regular basis. The T and B lymphocyte response to a variety of immunogens is being examined in collaboration with the Laboratory of Microbiology and Immunology. Carious lesions have started to develop in a number of animals.